#include<iostream>

using namespace std;
#define PI 3.1415926
#define MIN(a,b) (a<b ? a : b)

int main()
{   
    double r = 0;
    cout<<"Please input radius:"<<endl;
    cin>>r;
    double Area = PI * r * r;
    cout<<"radius="<<r<<",Area="<<Area;
    int a = 30,b=15;
    cout<<"min of 30,15>>"<<MIN(a,b)<<endl;
    return 0;
}